Theremin

Notable for its eerie sound, contact-less playing technique and its use in science fiction movies, Leon Theremin (great name) went down in musical history for this one. It was used memorably in Miklós Rózsa's soundtrack for Spellbound and The Lost Weekend, and Bernard Herrmann's soundtrack for The Day the Earth Stood Still.

Cheese Drums

Made from what appears to be a healthy speed of cheese genres, this kit probably won't survive too much percussive battering - best play with it Caerphilly. 

Cello Horn

This hybrid made the pages of Popular Science Monthly magazine back in 1936. The sound created by bowing the strings came out of the brass horn instead of via a traditional wooden body, reportedly producing a sound somewhere between strings and brass.

Stalacpipe Organ

Invented by the superbly named Leland W. Sprinkle in 1956 and situated in an underground cave in Virginia, the Great Stalacpipe Organ works by tapping on ancient stalactites with rubber mallets, all connected to a console that looks like a traditional organ. One of the popular stories surrounding the invention of the organ says that Sprinkle got the idea when his son hit his head on one of the stalactites, producing a low, vibrating hum from the cave.

Sharpsichord

Henry Dagg has one of the coolest sounding job titles ever - Sound Sculptor. In his amazingly awesome role as Sound Sculptor, Dagg invented the equally cool-sounding instrument known as the Sharpsichord. It's actually a gargantuan pin-barrel harp that contains 11 cylinders, and the pins strike internal strings as they rotate. 

Badgermin

So you've come to terms with the idea of the Theremin. It's fine, a bit of electronics, a spooky noise, nothing to worry about, right? Well, perhaps it's time you looked at the Badgermin. Just take a look at that word again. Badgermin. It's a badger crossed with a Theremin. It's a Badgermin.

Octobass

Constructed in 1850 by certifiable genius and fan of massive string instruments Jean-Baptiste Vuillaume, the Octobass is a chuffing massive double bass that stands at 3.48m tall. Which is ridiculous, really, seeing as it's too big to play with the hands - there are elaborate foot-pedals to make it possible. Apparently Berlioz was a fan, and wrote about it in his treatise on orchestration.

Hyperbass Flute

How about that for some seriously low-end flute? This aptly named flautist foghorn is the largest member of the flute family, containing over 15 metres in piping. It's a relativeley new instrument and, according to early reports, the tone is still under refinement as it's a bit growly. We don't care. It's massive and weird.

Hornucopian Dronepipe

The hornucopian dronepipe is an entirely 3D-printed instrument designed by MONAD Studio, Eric Goldemberg and Veronica Zalcberg with musician/luthier Scott F. Hall. It's just one of a set of rather dystopian-looking instruments which together form an art installation. The other instruments are: two-string piezoelectric violin, one-string electric travel bass guitar, one-string piezoelectric monovioloncello and a small didgeridoo.